Population Rarity and the Trophy Effect Because these cards were loose promos or included in boxes with minimal protection, the number of surviving Gem Mint copies is disproportionately low
This ability works wonderfully with unblockable creatures and your Ninjas, letting you sneak damage in, refilling your battlefield with a new creature that also has a form of evasion, while at the same time giving you a powerful blocker to deter oncoming attacks
Beyond just being powerful on its own, Insight Engine also works wonders with any Proliferate or counter-doubling effect
Of course, you get to draw a card at the end
Salandit From Stellar Miracle [R] Ember: 30 damage
A lot of the packages are also fairly small, so its relatively easy to patch them together